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To get an adapter so precisely as possible, I would love to take blueprints / drawings of motor and transmission with exactly dimensions but I can't find them or no where to find.
An exact measurement is quiet difficult to get the last hundredth.

So my questions are:
How do you build your adapterplates and motor couplings?
Do you straight begin to measure, or do you search the web or dealers?
Is there a good website or platform to get very good drawings?
Or do you hire someone to build one?
 

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To get an adapter so precisely as possible, I would love to take blueprints / drawings of motor and transmission with exactly dimensions but I can't find them or no where to find.
An exact measurement is quiet difficult to get the last hundredth.

So my questions are:
How do you build your adapterplates and motor couplings?
Do you straight begin to measure, or do you search the web or dealers?
Is there a good website or platform to get very good drawings?
Or do you hire someone to build one?
I'm in the process of designing an adapter plate right now. I have a small CNC machine that's pretty accurate, so you are correct in wanting the best "input" data possible to get the best results out. I'm going by measurements plus a bit of cheating. I have two options for my car, make an adapter plate that attaches to the bellhousing, or scrap the bellhousing and attach to the torque tube. The torque tube measurements are easy, the bolt holes line up on on even mm distances, so I don't have to measure to 3 decimal places. (and it's a simple rectangle) If I keep the bellhousing I will scan it (yep just put it on a scanner and import as a PDF) my CNC software will allow me to scale the image if necessary to physical measurements taken of the bellhousing, and accuracy depends on one or two critical measurements, not one for every hole in reference to every other hole and getting every angle correct.

My motor has documented mounting holes, so that part I don't have to worry about, but if you are using a forklift motor or something similar it would be a bit more difficult. However unlike the bellhousing there is a good chance they are all uniform in distance from center and spacing.

Because I don't have a lathe, I'm having the coupler made for me, that only required providing a clutch and some measurements.

****warning, my bellhousing is detachable and weights about 6-10lbs so it won't break my scanner, use common sense if using this idea****
 

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The easiest approach depends on the situation.

The usual case is making an adapter plate for a manual transmission where the bell housing mounting surface is on a single plane and the input shaft projects slightly beyond that plane.

The easy approach is to make a template out of foamboard or fiberboard. Start by drawing centerlines (horizontal/vertical alignment lines), drill a snug hole for the input shaft, and trace the outline of the bell housing.

The challenge is getting it precisely aligned. Transmission input shafts are often supported and aligned by the pilot bearing on the engine side. While there is some tolerance for minor misalignment, we can't be so far off that we preload the input shaft gears.

Each transmission is different, but there is often an obvious centerline and projecting dowels or sleeves that set the exact alignment. These are the only points that need precision. The rest of the bolt holes should be large enough to allow some movement -- non-sleeved bolt holes are not alignment points.

Again, it depends on the exact parts you are using. The Miata we are converting has bell housing bolt holes that are just a few mm lower than the horizontal centerline -- close enough that I was convinced that they had to be the centerline until precise measurements showed that not to be the case.

When you transfer the template to the plate you are going to cut, score both the centerlines and several concentric rings. These will make subsequent measurements much easier, since one of the first steps is removing the centerpoint.

We left our transmission adapter plate over-sized, with lifting holes on the top. As long as it fits in the engine bay or transmission tunnel, there isn't a reason to make it conform to the bell housing. You can cut it to the exact profile later, once everything is working.
 

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I always recommend measuring off of the engine, if you have it. The crankshaft is precisely centered, so there is no error from a trans input shaft wobble as mentioned above. If your vehicle has a sheetmetal plate between engine and trans you are in luck, as this is usually a precision fit to the dowel pins (which really are the only two holes that need to be precisely measured to the center). Just solidly mount a scribe to the crankshaft, this could be as simple as a transfer punch pushed through a tight hole drilled in an aluminum bar, bolted solidly to the crankshaft. Now turn the engine 360* and you have a perfectly centered circle to measure off of. There are many variations of this depending on vehicles (like extending the bar so the scribe goes through the center of the dowel hole,etc) If you don't have a sheetmetal plate factory, just make one up and securely mount it to the block.
Now you have an accurate template.
This is how we did it in the early days, before hi-tech measuring equipment!
Mike
www.EV-propulsion.com

DJB- you are right about the alignment dowels on the miata being just off the centerline-it would make things a heck of a lot easier if they were!
 

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Looks like you want something that looks profesionally made. When I made the adapter plate for my Ford Probe, I first made the adapter for the motor to transmission by taking the very end of the drive shaft where the flywheel bolts to and cut it off so I had a perfect flywheel bolt pattern. I also pulled the forklift motors output gear, made a centering tool that fit in both adapters and welded them together. Now that I had the adapter made, I put everything back into the car and lined it all up. I had about 1" of a gap with everything in place, so I bought a 1" aluminum plate, placed it against the tranny and marked it for cutting. I then had it cut at Coca-Cola (work) by a machinist, but I could've easily done it. It wasn't CNC but it looked good and worked great!
 

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There have been two piece adaptor plates made.

One plate is drilled to fit the bell housing and a large hole made in the centre.
The second plate is mounted to the motor and has bolt holes in it to bolt to the bell housing plate.

The trans is then stood on end so the bell housing plate is flat and level. The motor is then coupled to the trans but the plates are left free floating.
12v is applied to the motor and then it is nudged around until the shaft, coupler and trans sounds quiet and smooth. The two adaptor plates are then drilled and bolted together in that position.

It seems to have worked for a few people.
 

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I always recommend measuring off of the engine, if you have it. The crankshaft is precisely centered, so there is no error from a trans input shaft wobble as mentioned above. If your vehicle has a sheetmetal plate between engine and trans you are in luck, as this is usually a precision fit to the dowel pins (which really are the only two holes that need to be precisely measured to the center). Just solidly mount a scribe to the crankshaft, this could be as simple as a transfer punch pushed through a tight hole drilled in an aluminum bar, bolted solidly to the crankshaft. Now turn the engine 360* and you have a perfectly centered circle to measure off of. There are many variations of this depending on vehicles (like extending the bar so the scribe goes through the center of the dowel hole,etc) If you don't have a sheetmetal plate factory, just make one up and securely mount it to the block.
Now you have an accurate template.
This is how we did it in the early days, before hi-tech measuring equipment!
Mike
www.EV-propulsion.com

DJB- you are right about the alignment dowels on the miata being just off the centerline-it would make things a heck of a lot easier if they were!
WOW Mike I like the way you set this up, I think I could even do it that way!
Thanks car
now how to get a coupling
 

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By the way, you can cut steel with your circular saw with a metal cutting blade. Of course you cannot make a circle but you can easily make a hexagon or whatever and then finish the cuts with a saws-all.
 

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I didn't have the engine, so I cheated and got my errors of letting the motor/adapter settle down, then lifted it up, halved my distance and figured that was a good enough center. Side to side was easy enough to judge the same way once centered up and down.

Its really not as hard as people make it out to be.
 

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Who's using steel? Aluminum works great and is easier to cut. Did I miss something somewhere? Oops no smiley face icon?
I did a search on Ebay for aluminium plate for my original MR2 adaptor.

I searched based on the thicknesses I could use and found that there are a lot of fabricators selling the bigger offcuts from their scraps bin.
I also found big bits of aluminium plate at my regular scrap metal yard.

It works out a lot cheaper this way if you don't mind a few additional holes. Just make sure the pieces are flat though.:)
 

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Hi

I build right now an adapter for coupled an ADC 9" to a Ranger 94 transmission.
You can see how I align the center of the ADC shaft with the transmission shaft. You can find some kind of dial Indicators for 20$.
Because I don't have the original hollow dowel pin coming from the transmission, I put two new 1/4" dowel directly in the transmission frame.















 

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That looks a good method, Yabert.

Is there any radial movement on the gearbox primary shaft?
On some there is a little slop as there is only one bearing on the shaft and the front end is then held in the pilot bearing.
 

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Is there any radial movement on the gearbox primary shaft?
Yes! Around +/- 0.010" for this transmission shaft. But you can find the center with appropriately accuracy when you play with the shaft.

The front end is support by the pilot bearing in the fly wheel and this one is support by the motor shaft. The bearing with blue seal on picture align the fly wheel (transmission shaft) with the coupler mount on the ADC shaft.



 

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I used steel for mine. Racing rules require a 1/4 inch steel scatter shield, so the adapter is doing double duty. It seemed a waste to drape 1/4 inch steel over an aluminum adapter. Also, steel was easier to weld for Mr. Amateur welder here. Here are a couple links on how I made mine:

http://explodingdinosaurs.com/9electric/adapter/

http://explodingdinosaurs.com/9electric/adapter2

Who's using steel? Aluminum works great and is easier to cut. Did I miss something somewhere? Oops no smiley face icon?
 

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Yabert,

Beautiful job.

This should absolutly be placed as a sticky or go to the WIKI

Do any others of you guys agree?

Jim
 
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